Effects of ZnO coating on the performance of TiO2 nanostructured thin films for dye-sensitized solar cells

Cascade structure of TiO2/ZnO/CdS film for quantum dot sensitized solar cells

“…The red-shift in the IPCE spectrum of TiO 2 /ZnO/CdS cell as compared with the one of TiO 2 /CdS cell should be due to the strong light scattering [42] and lower band gap of CdS after ZnO coating. The result indicates that ZnO coating really facilitate the excited electron transport from CdS to TiO 2 film [28,32].…”

“…It can be observed that the I sc , V oc and Á have remarkably enhanced from 5.52 mA cm −2 , 0.49 V and 0.99% for TiO 2 /CdS cell to 7.66 mA cm −2 , 0.58 V and 1.56% for TiO 2 /ZnO/CdS cell. The improvement of I sc and V oc are caused by the formation of an inherent barrier layer at the TiO 2 /CdS interface [28][29][30][31] and the passivation of the surface traps on the TiO 2 film by ZnO coating [30][31][32], which reduces the charge recombination and favors the electron transport.…”

“…Wu et al [27] fabricated ZnO-coated TiO 2 electrode by rf magnetron sputtering to increase the efficiency of DSSCs by 38% from 4.76% to 6.55%. Kao et al [28] studied DSSCs based on ZnO-coated TiO 2 film fabricated by sol-gel method and found that the conversion efficiency was increased to 3.24% as compared with 2.5% for DSSC based on bare TiO 2 film. Kim et al [29] prepared TiO 2 /ZnO/Eosin Y films by onestep cathodic electrodeposition method for photoanode of DSSCs and found that the efficiency was increased from 2.6% for the cell without ZnO interlayer to 4.4%.…”

ZnO Spin-Coating of TiO<sub>2</sub> Photo-Electrodes to Enhance the Efficiency of Associated Dye-Sensitized Solar Cells

“…At the smallest precursor concentration 0.1 M, there is a clear enhancement of the short circuit photocurrent J SC from 5.73 to 7.48 mA/cm 2 , while small shifts [12,13]. This recombination inhibition is the direct cause of the photocurrent enhancement occurring at ZnO precursor concentrations around 0.1 M. However, there must be an optimal amount of ZnO in the deposited layer above which the illuminated TiO 2 surface is partially obscured by the ZnO layer.…”

“…However, the deposition of a ZnO layer on the surface of a nanoporous TiO 2 film to improve the DSSC photovoltaic properties is an active issue in the context related to surface treatment of TiO 2 photo-electrodes by thin metal oxide films [7][8][9][10][11]. Kao et al [12] employed the sol-gel spin-coating method to prepare TiO 2 and ZnO spin-coated TiO 2 electrodes for DSSCs. Multilayer coating was applied to TiO 2 to reach the required thickness and a monolayer of ZnO was applied to spin-coat the TiO 2 film.…”